Stabilizer for solid preparation of pesticide and use thereof

Abstract

The application relates to a stabilizer for a pesticide solid preparation and application thereof, and relates to the technical field of pesticide preparation auxiliary materials; components such as copolymerized povidone S-630, calcium oxide, anhydrous sodium sulfate and dodecylamine polyoxyethylene ether are combined to prepare a stabilizer for a pesticide solid preparation, the 14-day heat storage (54 DEG C) stability of pesticide components such as nitenpyram and carbosulfan is taken as an evaluation index, the combination and the dosage ratio of different stabilizers are optimized, and a better formula is determined, so that a stabilizer capable of significantly improving the stability of pesticide components such as nitenpyram and carbosulfan is screened.

Description

Technical Field

[0001] This invention relates to the field of auxiliary materials for pesticide preparation, specifically to a stabilizer for solid pesticide formulations and its application. Background Technology

[0002] Some pesticide active ingredients are prone to decomposition due to long storage periods. However, different types of pesticides have different decomposition mechanisms, requiring different stabilizers to control their decomposition. For example, pesticides such as thiamethoxam and acetamiprid also suffer from long storage times and easy decomposition in actual production and use. Acetaminophen is a neonicotinoid insecticide with unique chemical and biological properties. It shows excellent activity against various aphids, whiteflies, rice leafhoppers, and thrips. Because acetamiprid technical is easily soluble in water and decomposes readily in water, even when prepared as a solid formulation, it easily absorbs moisture from the air, resulting in poor stability. Due to the stability issues of acetamiprid, it cannot meet the requirement that the decomposition rate of the active ingredient in pesticide products should be less than 5% after two years of storage at room temperature, resulting in a short shelf life for products containing acetamiprid. Many companies have abandoned production and sales due to the instability of this ingredient and the high market risk, leading to the idle and wasted registration certificates for acetamiprid products. Acetaminophen decomposes rapidly. Within 3 months of production and storage at room temperature, its content decomposition rate is greater than 5%, and within 6 months of storage, the content decomposition rate is greater than 10%. If the content of acetamiprid is too low, the efficacy will be poor.

[0003] In view of the above reasons, in order to make up for the shortcomings of existing technologies, a new pesticide stabilizer has been developed for use in solid formulations of thiamethoxam or acetamiprid. This stabilizer can effectively slow down the decomposition rate of thiamethoxam and acetamiprid, improve their stability, and extend their shelf life. Summary of the Invention

[0004] In view of the shortcomings of the prior art, the purpose of this invention is to provide a stabilizer for solid pesticide formulations used in thiamethoxam or acetamiprid, which can effectively slow down the decomposition rate of thiamethoxam or acetamiprid, improve the stability of thiamethoxam or acetamiprid, and extend the shelf life of thiamethoxam or acetamiprid, and its application therein.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: a stabilizer for a pesticide solid formulation, wherein the stabilizer for the pesticide solid formulation includes copovidone S-630, and one or more of calcium oxide, dodecylamine polyoxyethylene ether, and anhydrous sodium sulfate; wherein the mass percentage of copovidone S-630 in the total mass of the stabilizer for the pesticide solid formulation is 70-95%.

[0006] Furthermore, the stabilizer of the pesticide solid formulation is a binary compound of copovidone S-630 and dodecylamine polyoxyethylene ether; the mass ratio of copovidone S-630 to dodecylamine polyoxyethylene ether is 9:1 to 3:1.

[0007] Furthermore, the stabilizer of the pesticide solid formulation is a binary compound of copovidone S-630 and dodecylamine polyoxyethylene ether; the mass ratio of copovidone S-630 to dodecylamine polyoxyethylene ether is 5:1.

[0008] Furthermore, the stabilizer of the pesticide solid formulation, by weight, includes: copovidone S-630: 100 parts, dodecylamine polyoxyethylene ether: 10-14 parts, and anhydrous sodium sulfate: 3-5 parts.

[0009] Furthermore, the stabilizer of the pesticide solid formulation, by weight, includes: copovidone S-630: 100 parts, dodecylamine polyoxyethylene ether: 12-14 parts, and anhydrous sodium sulfate: 4-5 parts.

[0010] Furthermore, the stabilizer in the pesticide solid formulation accounts for 1-15% of the total mass of the pesticide solid formulation.

[0011] The present invention also provides the application of the stabilizer of the aforementioned pesticide solid formulation in the preparation of pesticide wettable powders, pesticide water-dispersible granules, seed treatment dry powders, or pesticide soluble granules.

[0012] The present invention also provides a pesticide solid formulation comprising a stabilizer of the aforementioned pesticide solid formulation, comprising the pesticide active ingredient and the stabilizer of the pesticide solid formulation; the mass percentage of the stabilizer of the pesticide solid formulation is 1-15% of the total mass of the pesticide solid formulation, and the remainder is an acceptable carrier, adjuvant, and pesticide active ingredient.

[0013] Furthermore, the pesticide solid formulation is thiocarbofuran seed treatment dry powder, which is composed of the following components by weight percentage: 20-50% pesticide active ingredient, 2-10% dispersant, 1-10% wetting agent, 2-15% stabilizer, 1-5% warning agent, and the balance being diatomaceous earth; the pesticide active ingredient is thiocarbofuran.

[0014] Furthermore, the pesticide solid formulation is a solid formulation containing acetamiprid, and the pesticide solid formulation is composed of the following components by weight percentage: 5-60% pesticide active ingredient, 2-10% dispersant, 1-10% wetting agent, 2-15% stabilizer of the pesticide solid formulation, 1-5% warning agent, and the balance being sodium sulfate or kaolin; the pesticide active ingredient is obtained by mixing acetamiprid or acetamiprid with other pesticide components.

[0015] This invention discloses a stabilizer for solid pesticide formulations and its application. The stabilizer is prepared by combining components such as copovidone S-630, calcium oxide, anhydrous sodium dihydrogen phosphate, anhydrous sodium sulfate, and dodecylamine polyoxyethylene ether. The stability of pesticide components such as acetamiprid and carbofuran during 14 days of heat storage (54°C) is used as an evaluation index. Different combinations of stabilizers and their dosage ratios are optimized to determine the best formulation, thereby screening for stabilizers that can significantly improve the stability of pesticide components such as acetamiprid and carbofuran. Different stabilizers are then... When compounding pesticides, the performance of the resulting composite stabilizers varies significantly due to the substantial differences in their physicochemical properties. Some composite stabilizers can significantly improve the stability of active ingredients such as carbofuran or acetamiprid in pesticide formulations. However, some stabilizers are not only incompatible with each other but also conflict with the properties of the pesticide technical material. Improper compatibility can not only fail to improve the stability of the formulation but may even reduce it, thereby decreasing the control efficacy. The inventors have discovered that acetamiprid or... The stability of carbofuran is related to water content. When the molar ratio of residual water to carbofuran is less than 0.65, carbofuran is stable. When the molar ratio of residual water to acetamiprid is greater than 0.65, carbofuran becomes unstable under heat storage, with a decomposition rate greater than 5%. Acetaminophen, on the other hand, has a considerably high decomposition rate when the moisture content is greater than 0.5%. Acetaminophen decomposes rapidly, mainly because a small amount of moisture is introduced into the solid formulation during production due to some raw materials or absorbed from the air during storage, leading to the degradation of the solid formulation containing acetamiprid. High decomposition rate and short shelf life when exposed to water; however, the stabilizer of the pesticide solid formulation of this invention includes copovidone S-630, as well as one or more of calcium oxide, dodecylamine polyoxyethylene ether, and anhydrous sodium sulfate. The intramolecular acyl structure of copovidone S-630 combines with the hydroxyl functional groups in water, thereby absorbing the water in the acetamiprid fixed formulation. Under the action of the composite stabilizer, it can effectively slow down the decomposition rate of thiocarbamate and acetamiprid, improve the stability of the active ingredients such as thiocarbamate and acetamiprid in the pesticide formulation, and effectively extend the shelf life of the product.

[0016] This invention relates to a stabilizer for solid pesticide formulations and its application. The stabilizer is composed of copovidone S-630, dodecylamine polyoxyethylene ether, and anhydrous sodium sulfate. It significantly slows down the decomposition rate of thiocarbamate and acetamiprid, significantly improves the stability of active ingredients such as thiocarbamate and acetamiprid in pesticide formulations, and effectively extends the shelf life of the product. Detailed Implementation

[0017] The following embodiments can help those skilled in the art to more fully understand the present invention, but should not be construed as limiting the present invention in any way.

[0018] I. 35% Butylcarbofuran Seed Treatment Dry Powder

[0019] 1. Formulation Preparation Examples: In Example 1, the content of copovidone S-630 as a stabilizer was 70%; in Example 2, the content of copovidone S-630 as a stabilizer was 95%; in Example 3, the content of copovidone S-630 as a stabilizer was 80%; in Example 4, the stabilizer, by weight, included: copovidone S-630: 100 parts, dodecylamine polyoxyethylene ether: 10 parts, and anhydrous sodium sulfate: 3 parts; in Example 5, the stabilizer, by weight, included: copovidone S-630: 100 parts, dodecylamine polyoxyethylene ether: 14 parts, and anhydrous sodium sulfate: 5 parts.

[0020] 1.1 35% Butylcarbofuran Seed Treatment Dry Powder

[0021] Table 1. Formulation composition of 35% Butylcarbofuran seed treatment dry powder

[0022]

[0023]

[0024] The preparation methods for Examples 1-5 and Comparative Examples 1-5 are as follows: Silica is adsorbed onto thiocarbamate crude oil, and then the above materials are mixed and pulverized evenly to prepare a seed treatment dry powder. Anhydrous calcium chloride and calcium oxide in Comparative Example 5 both belong to calcium-containing compounds and have hygroscopic properties. The samples prepared in Examples 1-5 and Comparative Examples 1-5 have excellent appearance and flowability, with no clumping.

[0025] 1.2 Stability test of the 35% carbofuran seed treatment powder in the above examples:

[0026] Stability tests of 35% carbofuran seed treatment powder under heat and ambient temperature storage:

[0027] The carbofuran seed treatment powders prepared in Examples 1-4 and Comparative Examples 1-4 were used as samples. Each prepared sample was divided into 9 equal parts, each weighing 200 grams, sealed in aluminum foil bags, and stored at room temperature, 54°C, and frozen, respectively. Each treatment was repeated 3 times. After 14 days, the carbofuran content and other indicators were tested according to "GB-T 19136-2003 Method for Determination of Thermal Stability of Pesticides", "GB-T 19137-2003 Method for Determination of Low Temperature Stability of Pesticides", and "NY / T 1427-2016 General Rules for Stability Testing of Pesticides at Room Temperature". Based on the experimental results, the effect of calcium oxide on the storage stability of carbofuran seed treatment powders was evaluated. In the table below, carbofuran is represented by thiocarbofuran. The molar ratio of residual water to carbofuran is represented by H.

[0028] Table 2. Results of storage stability test of 35% carbofuran seed treatment powder

[0029]

[0030]

[0031] Each of the above treatments was repeated three times, and the average value was taken.

[0032] The table above shows that the decomposition rate of the active ingredient, carbofuran, in Examples 1-5 and Comparative Examples 1-5 after 14 days of heat storage at 54°C was less than 5%. After 6-24 months of storage at room temperature, the decomposition rate of carbofuran in Examples 1-4 was also less than 5%, meeting the enterprise standard requirements for this product. Conversely, under the same storage conditions without the addition of the stabilizer of this invention, the average decomposition rate of carbofuran in Comparative Examples 1-4 was 12.34% (6 months), 19.62% (12 months), 23.85% (18 months), and 28.57% (24 months), respectively, far exceeding 5%, and failing to meet the enterprise standard requirements for this product. When the carbofuran seed treatment dry powder is stored for a long period, moisture from the air can enter the packaging. Upon contact with moisture, carbofuran decomposes rapidly into furadan. In Example 5 and Comparative Example 5, the decomposition rate of carbofuran was higher than 5% after 6-24 months of storage at room temperature, and the decomposition rate was as high as 20% or more after 24 months of storage.

[0033] In Examples 1-5 of this invention, a stabilizer was added. When the carbofuran seed treatment powder is stored at room temperature, it absorbs moisture from the air, preventing the moisture from becoming free and reacting with the active ingredient carbofuran. This improves the stability of carbofuran under room temperature storage conditions and extends the shelf life of the carbofuran product. In Examples 1-5 and Comparative Examples 1-5, after 7 days of cold storage at 0℃, the decomposition rate of carbofuran was less than 5%, meeting the enterprise standard requirements for this product.

[0034] 1.3. Stability test of 35% carbofuran seed treatment powder diluted with water:

[0035] Test method: Dissolve and disperse 2g of sample in 8g of water and stir well. At time points of 12h, 24h, and 48h, add 40g of methanol and mix well. Then, detect the content of carbofuran in the sample aqueous solution. Each sample is tested in triplicate, and the average value is taken.

[0036] Table 3. Stability test results of 35% carbofuran seed treatment powder diluted with water.

[0037]

[0038] As shown in the table above, when the active ingredient thiocarbofuran in Examples 1-5 is diluted with water, its decomposition rate in water is less than 5% after 12h, 24h, and 48h. The decomposition rates of thiocarbofuran in Comparative Examples 1-5 in water are greater than those in Examples 1-5.

[0039] II. 25% Acetaminophen·Isoprocarb Wettable Powder

[0040] 2.1 Preparation of 25% acetamiprid·isoprocarb wettable powder:

[0041] The masterbatch formulation of 25% acetamiprid·isoprocarb wettable powder consists of: acetamiprid (97%) 5.16g, isoprocarb (98%) 20.5g, sodium naphthalene sulfonate formaldehyde polymer (NNO) 5g, sodium polynaphthalene formaldehyde sulfonate (MF dispersant) 5g, silica 5g, and kaolin to 87.5g.

[0042] Example 6

[0043] Weigh 875g of the master powder of 25% acetamiprid·isoprocarb wettable powder, then add 100g of copovidone S-630 and 25g of anhydrous sodium sulfate, and mix and stir evenly.

[0044] Comparative Example 6-1

[0045] Weigh 875g of the master powder of 25% acetamiprid·isoprocarb wettable powder, then add 125g of calcium oxide and mix thoroughly.

[0046] Comparative Example 6-2

[0047] Weigh 875g of the master powder of 25% acetamiprid·isoprocarb wettable powder, then add 125g of anhydrous sodium sulfate and mix thoroughly.

[0048] 2.2 Stability test of 25% acetamiprid·isoprocarb wettable powder:

[0049] The 25% acetamiprid·isoprocarb wettable powders prepared in Examples 6, 6-1, and 6-2 were used as samples. Each sample was divided into nine equal portions, each weighing 200 grams, sealed in aluminum foil bags, and subjected to pre-storage, heat storage at 54°C, and cold storage at 0°C, respectively. Each treatment was repeated three times. After 14 days, the acetamiprid content and other indicators were tested according to the standards in "GB-T19136-2003 Test Method for Heat Storage Stability of Pesticides", "GB-T 19137-2003 Test Method for Low Temperature Stability of Pesticides", and "NY / T1427-2016 General Rules for Stability Testing of Pesticides at Room Temperature". Based on the experimental results, the effect of calcium oxide on the storage stability of 25% acetamiprid·isoprocarb wettable powder was evaluated.

[0050] Table 4. Test results of storage stability of 25% acetamiprid·isoprocarb wettable powder

[0051]

[0052] In Example 6, the 25% acetamiprid·isoprocarb wettable powder showed a decomposition rate of less than 5% after cold storage (0°C, 7 days) and hot storage (54°C, 14 days), which met the standard requirements.

[0053] As shown in the table above, the decomposition rate of acetamiprid in the sample of Example 6 after heat storage (54°C) for 14 days was 2.61%, which is less than the standard requirement of 5% for acetamiprid; the moisture content was 0.3%, which is less than the standard requirement of 0.5%. The decomposition rates of acetamiprid in the samples of Comparative Examples 6-1 and 6-2 after heat storage (54°C) for 14 days were 39.18% and 36.57% higher than that of acetamiprid in Example 6, respectively. The stability of acetamiprid was greatly improved by the addition of the stabilizer of the present invention.

[0054] Table 5. Results of room temperature storage stability test for 25% acetamiprid·isoprocarb wettable powder

[0055]

[0056] The 25% acetamiprid·isoprocarb wettable powder of Example 6 showed an isoprocarb decomposition rate of less than 5% after 6, 12, 18, and 24 months of storage at room temperature, which meets the standard requirements.

[0057] As shown in the table above, after 6, 12, 18, and 24 months of storage at room temperature, the decomposition rate of acetamiprid in the sample of Comparative Example 6-1 was 8.21%, 14.55%, 18.84%, and 22.57% higher than that in Example 6, respectively. The decomposition rate of acetamiprid in the sample of Comparative Example 6-2 was 3.36%, 10.26%, 16.23%, and 19.96% higher than that in Example 6, respectively. Therefore, adding the stabilizer of this invention to the formulation of 25% acetamiprid·isoprocarb wettable powder not only reduces the risk of excessive moisture absorption from the air during storage but also significantly improves the stability of the active ingredient acetamiprid, extending the product's shelf life.

[0058] 2.3 Stability test of 25% acetamiprid·isoprocarb wettable powder diluted with water

[0059] Test method: 25% acetamiprid·isoprocarb wettable powder was diluted 100 times with water. The acetamiprid content in the aqueous solution was measured at 12h, 24h, and 48h. Each sample was tested in triplicate, and the average value was taken. The isoprocarb decomposition rate of 25% acetamiprid·isoprocarb wettable powder after 12h, 24h, and 48h was less than 5%, meeting the standard requirements.

[0060] Table 6. Stability test results of 25% acetamiprid·isoprocarb wettable powder diluted with water.

[0061]

[0062] As shown in the table above, the decomposition rates of acetamiprid in Examples 6, 6-1, and 6-2 after dilution with water for 12 hours, 24 hours, and 48 hours were all less than 5%. Pesticides are generally prepared and used immediately after dilution, meaning they should be sprayed immediately after dilution, and the spraying time should not exceed 6 hours.

[0063] III. 50% acetamiprid soluble granules

[0064] 3.1 Table 7 Preparation of 50% acetamiprid soluble granules

[0065]

[0066] According to the formulations of Examples 7, 8, 9, Comparative Examples 7-A, 7-B, 7-C, and 7-D, the weight of each component was weighed, and the materials except anhydrous ethanol were mixed evenly. Then, the mixture was pulverized by air jet milling, and finally anhydrous ethanol was added for granulation to obtain 50% acetamiprid soluble granules with uniform size and good flowability.

[0067] 3.2 Stability test of 50% acetamiprid soluble granules:

[0068] The 50% acetamiprid soluble granules prepared in Examples 7, 8, 9, Comparative Examples 7-A, 7-B, 7-C, and 7-D were used as samples. Each prepared sample was divided into 9 equal parts, each weighing 200 grams, sealed in aluminum foil bags, and subjected to pre-storage, heat storage at 54°C, and cold storage at 0°C, respectively. Each treatment was repeated 3 times. After 14 days, the acetamiprid content and other indicators were tested according to "GB-T 19136-2003 Method for Determination of Thermal Stability of Pesticides", "GB-T 19137-2003 Method for Determination of Low-Temperature Stability of Pesticides", and "NY / T 1427-2016 General Rules for Stability Testing of Pesticides at Room Temperature". Based on the test results, the effect of the composition of stabilizer copovidone S-630 and dodecylamine polyoxyethylene ether on the storage stability of 50% acetamiprid soluble granules was evaluated.

[0069] Table 8. Test results of storage stability of 50% acetamiprid soluble granules

[0070]

[0071] As shown in the table above, the decomposition rate of acetamiprid in the above samples stored at 54℃ for 14 days was less than the standard requirement of 5% for acetamiprid; the moisture content was less than the standard requirement of 0.5%; and the content and decomposition rate of cold-stored samples also met the standard requirements.

[0072] Table 1: Results of Room Temperature Storage Stability Test for 950% Acetaminophen Soluble Granules

[0073]

[0074] As shown in the table above, in Example 9 and Comparative Example 7-A, the decomposition rates of acetamiprid were 3.17% and 4.55%, respectively, less than 5% after 6 months of storage at room temperature, meeting the standard requirements. However, after 12-24 months, the decomposition rates of acetamiprid were greater than 5%, and the moisture content was greater than 0.5%, indicating a short shelf life. In contrast, the acetamiprid in Comparative Examples 7-B, 7-C, and 7-D showed decomposition rates greater than 5% and moisture content greater than 0.5% after 6, 12, 18, and 24 months of storage at room temperature, respectively, and exhibited clumping, failing to meet the requirements for soluble pesticide granules.

[0075] Meanwhile, the table above also shows that when stored at room temperature for 6 months, 12 months, 18 months, and 24 months, the decomposition rate of acetamiprid in Example 9, Comparative Example 7-A, Comparative Example 7-B, Comparative Example 7-C, and Comparative Example 7-D is higher than that in Example 7. Among them, the decomposition rate of acetamiprid in Example 9 was 0.54%, 1.38%, 1.75%, and 2.23% lower than that in Example 7; the decomposition rate of acetamiprid in Comparative Example 7-A was 3.06%, 5.6%, 9.08%, and 12.11% higher than that in Example 7; the decomposition rate of acetamiprid in Comparative Example 7-B was 4.04%, 8.82%, 11%, and 19.18% higher than that in Example 7; the decomposition rate of acetamiprid in Comparative Example 7-C was 5.84%, 15.23%, 22.45%, and 25.42% higher than that in Example 7; and the decomposition rate of acetamiprid in Comparative Example 7-D was 4.97%, 13.52%, 16.85%, and 21.32% higher than that in Example 7.

[0076] Similarly, the decomposition rates of acetamiprid in Comparative Examples 7-A, 7-B, 7-C, and 7-D were all higher than those in Example 8.

[0077] In conclusion, the addition of the stabilizer of this invention to the formulation of 50% acetamiprid soluble granules not only solves the problem of high decomposition rate of acetamiprid during storage and extends the shelf life of the product, but also reduces the problem of product clumping and poor flowability caused by moisture absorption from the air during storage.

[0078] 3. Stability test of 350% acetamiprid soluble granules diluted in water

[0079] Test method: 50% acetamiprid soluble granules were diluted 100 times with water, and the acetamiprid content in the aqueous solution was detected at 12h, 24h, and 48h. Each sample was tested in triplicate, and the average value was taken.

[0080] Table 10. Stability test results of 50% acetamiprid soluble granules diluted with water.

[0081]

[0082] As shown in the table above, the decomposition rate of acetamiprid in Examples 7, 8, and 9 after dilution with water for 12 hours and 24 hours was less than 5%, but the decomposition rate was greater than 5% after dilution with water for 48 hours. The decomposition rates of acetamiprid in Comparative Examples 7-A, 7-B, 7-C, and 7-D after dilution with water for 12 hours, 24 hours, and 48 hours were all greater than 5%. Pesticide products are generally prepared and used immediately after dilution, meaning they should be sprayed immediately after dilution, and the spraying time should not exceed 12 hours.

[0083] IV. 25% acetamiprid·pymetrozine wettable powder (1:1)

[0084] 4.1 Preparation of 25% acetamiprid·pymetrozine wettable powder

[0085] The masterbatch formulation of 25% acetamiprid·pymetrozine wettable powder consists of: acetamiprid (97%) 12.9g, pymetrozine (98%) 12.8g, sodium dodecyl sulfate (K12) 5g, silica 10g, and kaolin to 75g.

[0086] Example 10

[0087] Weigh 750g of the masterbatch of 25% acetamiprid·pymetrozine wettable powder, then add 200g of copovidone S-630 and 50g of calcium oxide, and mix thoroughly.

[0088] Comparative Example 10-1

[0089] The difference from Example 10 is that kaolin is used instead of copovidone S-630.

[0090] Comparative Example 10-2

[0091] The difference from Example 10 is that copovidone S-630 was replaced with anhydrous calcium chloride.

[0092] 4.2 Stability test of 25% acetamiprid·pymetrozine wettable powder

[0093] The 25% acetamiprid·pymetrozine wettable powders prepared in Examples 10, 10-1, and 10-2 were used as samples. Each sample was divided into nine equal portions, each weighing 200 grams, sealed in aluminum foil bags, and subjected to pre-storage, heat storage at 54°C, and cold storage at 0°C, respectively. Each treatment was replicated three times. After 14 days, the acetamiprid content and other indicators were tested according to the standards in "GB-T19136-2003 Test Method for Heat Storage Stability of Pesticides", "GB-T 19137-2003 Test Method for Low Temperature Stability of Pesticides", and "NY / T 1427-2016 General Rules for Stability Testing of Pesticides at Room Temperature". Based on the test results, the effect of stabilizers on the storage stability of 25% acetamiprid·pymetrozine wettable powder was evaluated.

[0094] Table 11. Test results of storage stability of 25% acetamiprid·pymetrozine wettable powder

[0095]

[0096] After cold storage (0°C, 7 days) and hot storage (54°C, 14 days) of the 25% acetamiprid·pymetrozine wettable powder in Example 10, the decomposition rate of pymetrozine was less than 5%, which met the standard requirements.

[0097] As shown in the table above, the decomposition rate of acetamiprid in the sample of Example 10 after heat storage (54°C) for 14 days was 2.16%, which is less than the standard requirement of 5% for acetamiprid; the moisture content was 0.35%, which is less than the standard requirement of 0.5%. The decomposition rates of acetamiprid in the samples of Comparative Examples 10-1 and 10-2 after heat storage (54°C) for 14 days were 10.11% and 2.24% higher than that of acetamiprid in Example 10, respectively. Clearly, the addition of the stabilizer of this invention significantly improves the heat storage stability of acetamiprid.

[0098] Table 12 Results of the room temperature storage stability test for 25% acetamiprid·pymetrozine wettable powder

[0099]

[0100] The 25% acetamiprid·pymetrozine wettable powder of Example 10 showed a decomposition rate of less than 5% after 6, 12, 18, and 24 months of storage at room temperature, and also exhibited good stability.

[0101] As shown in the table above, after 6, 12, 18, and 24 months of storage at room temperature, the decomposition rate of acetamiprid in the sample of Comparative Example 10-1 was 9.26%, 12.19%, 13.12%, and 21.06% higher than that in Example 10, respectively; and the decomposition rate of acetamiprid in the sample of Comparative Example 10-2 was 4.86%, 6.79%, 9.57%, and 16.67% higher than that in Example 10, respectively. Clearly, the addition of the stabilizer of this invention to the formulation of 25% acetamiprid·isoprocarb wettable powder not only reduces the absorption of moisture from the air during storage but also improves the stability of the active ingredient acetamiprid, thus extending the shelf life of the product.

[0102] 3.3 Stability test of 25% acetamiprid·pymetrozine wettable powder diluted with water

[0103] Test method: 25% acetamiprid·pymetrozine wettable powder was diluted 100 times with water, and the acetamiprid content in the aqueous solution was detected at 12h, 24h, and 48h. Each sample was tested in triplicate, and the average value was taken.

[0104] Table 13. Stability test results of 25% acetamiprid·pymetrozine wettable powder diluted with water.

[0105]

[0106]

[0107] As shown in the table above, the decomposition rates of acetamiprid in Examples 10, 10-1, and 10-2 after dilution with water for 12 hours, 24 hours, and 48 hours were all less than 5%. Pesticides are generally prepared and used immediately after dilution, meaning they should be sprayed within 24 hours of dilution.

[0108] The above test results indicate that the stabilizer for a pesticide solid formulation of the present invention and its application, using a combination of components such as copovidone S-630, calcium oxide, anhydrous sodium dihydrogen phosphate, anhydrous sodium sulfate, and dodecylamine polyoxyethylene ether, is formulated as a stabilizer for a pesticide solid formulation. The stability of pesticide components such as acetamiprid and carbofuran during 14 days of heat storage (54℃) is used as an evaluation index. Different combinations of stabilizers and their dosage ratios are optimized to determine the best formulation, thereby screening for stabilizers that can significantly improve the stability of pesticide components such as acetamiprid and carbofuran. The stabilizer for the pesticide solid formulation of the present invention includes copovidone S-630, as well as calcium oxide, dodecylamine polyoxyethylene ether, and... One or more of anhydrous sodium sulfate, copovidone S-630, binds its intramolecular acyl structure to hydroxyl functional groups in water, thereby absorbing moisture from the immobilized acetamiprid formulation. With the action of a composite stabilizer, it effectively slows down the decomposition rate of thiocarbamate and acetamiprid, improving the stability of active ingredients such as thiocarbamate and acetamiprid in pesticide formulations and effectively extending the product's shelf life. The stabilizer is a compound of copovidone S-630, dodecylamine polyoxyethylene ether, and anhydrous sodium sulfate, which significantly slows down the decomposition rate of thiocarbamate and acetamiprid, significantly improving the stability of active ingredients such as thiocarbamate and acetamiprid in pesticide formulations and effectively extending the product's shelf life.

[0109] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A solid preparation of a pesticide, characterized by comprising The pesticide solid formulation is 50% acetamiprid soluble granules, and the 50% acetamiprid soluble granules are composed of any of the following components in the specified proportions. composition: (1) Based on 100g, 51.55g of 97% acetamiprid, 5g of sodium dodecyl sulfate, 3g of sodium alkyl naphthalene sulfonate, 1.5g of copovidone S-630, 0.5g of dodecylamine polyoxyethylene ether, 5g of anhydrous ethanol, and sodium sulfate to make up to 100g. (2) Based on 100g, 51.55g of 97% acetamiprid, 5g of sodium dodecyl sulfate, 3g of sodium alkyl naphthalene sulfonate, 1.8g of copolyvinylpyrrolidone S-630, 0.2g of dodecylamine polyoxyethylene ether, 5g of anhydrous ethanol, and sodium sulfate to make up to 100g.

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